On Mon, May 30, 2022 at 11:09:11AM +0200, Pali Rohár wrote:
Original ubifs code was designed that after ubifs_umount() call it is required to also call ubi_close_volume() which closes underlying UBI volume. But U-Boot ubifs modification have not implemented it properly which caused that ubifsumount command contains resource leak. It can be observed by calling simple sequence of commands:
=> ubi part mtd2 ubi0: attaching mtd2 ... => ubifsmount ubi0 => ubifsumount Unmounting UBIFS volume rootfs! => ubi detach ubi0 error: ubi_detach_mtd_dev: ubi0 reference count 1, destroy anyway ubi0: detaching mtd2 ubi0: mtd2 is detached
Fix this issue by calling ubi_close_volume() and mutex_unlock() in directly in ubifs_umount() function before freeing U-Boot's global ubifs_sb. And remove duplicate calls of these two functions in remaining places. Note that when ubifs_umount() is not called then during error handling is still needed to call ubi_close_volume() and mutex_unlock.
With this change ubifsumount command does not throw that error anymore:
=> ubi part rootfs ubi0: attaching mtd2 ... => ubifsmount ubi0 => ubifsumount Unmounting UBIFS volume rootfs! => ubi detach ubi0: detaching mtd2 ubi0: mtd2 is detached
Signed-off-by: Pali Rohár pali@kernel.org
Applied to u-boot/next, thanks!